1. Field of the Invention
The present invention is directed to glued screens for vibratory separator apparatuses and shale shakers; to methods for making such screens; to automated methods for making such screens; to screens made by such methods; to machines for making such screens, and to vibratory separator apparatuses and shale shakers with such screens.
2. Description of Related Art
The need for solids control in drilling mud used in hydrocarbon well drilling is well known in the prior art. Drilling mud, typically a mixture of clay and water and various additives, is pumped down through a hollow drill string (pipe, drill collar, bit, etc.) into a well being drilled and exits through holes in a drillbit. The mud picks up cuttings (rock) and other solids from the well and carries them upwardly away from the bit and out of the well in a space between the well walls and the drill string. At the top of the well, the solids-laden mud is discharged over a shale shaker, a device which typically has a series of screens arranged in tiered or flat disposition with respect to each other.
The prior art discloses a wide variety of vibrating screens, devices which use them, shale shakers, and screens for shale shakers. The screens catch and remove solids from the mud as the mud passes through them. If drilled solids are not removed from the mud used during the drilling operation, recirculation of the drilled solids can create weight, viscosity, and gel problems in the mud, as well as increasing wear on mud pumps and other mechanical equipment used for drilling.
The present invention discloses, in at least certain aspects, methods for making screen assemblies for vibratory separators and shale shakers, the method including applying glue in a glue pattern to at least one layer of screening material useful for screening fluid introduced to a vibratory separator or shale shaker, the applying done by powered moving mechanical glue application apparatus; and, in one aspect, the glue is heated moisture-curing hot melt glue. Such methods may also include applying moisture to glue in a glue pattern following application of moisture-curing hot melt glue to layer(s) of screening material.
The present invention discloses, in at least certain embodiments, methods for making a screen or screen assembly for a vibratory separator or shale shaker, the method including: moving with screen movement apparatus at least one layer of screening material below a glue application apparatus, the glue application apparatus including a main body and a plurality of movable glue nozzles movably connected to the main body; moving the movable glue nozzles with nozzle movement apparatus above the at least one layer of screening material; applying with the movable glue nozzles an amount of glue flowing from the glue nozzles in a pattern to at least a portion of the at least one layer of screening material, and allowing the glue to cure.
In certain aspects the present invention provides a method and machines for making a glued-together combination of two, three or more layers of screening material. In certain aspects the thus-produced combination is suitable for use in screen assemblies used on shale shakers, with or without screen assembly lower support structure or apparatus for the screening material layer(s).
The present inventors have recognized that: a first layer of screening material moved beneath glue applying nozzles that apply a desired glue pattern is, preferably, stabilized and/or held in tension relatively tight and flat as it moves beneath the glue nozzle(s), to inhibit vibration of it, and to facilitate the application of a uniform glue pattern of uniform glue bead thickness across a major part of or over substantially all of the surface of the screening material; moisture-cure hot-melt glue is, in certain aspects, cured more quickly by applying water to the glue before and/or while it cures than by air exposure, before removing the screen combination from a machine, before rolling the thus-produced screen combination up on a roll, and/or before setting it aside for glue curing by air exposure; hot-melt molten glue is used, preferably, which does not pass quickly through layer(s) of screening material to which it is being applied due to its viscosity; hot-melt molten glue can be moved up from a lower layer to which it is initially applied (e.g., but not limited to a relatively coarse layer such as 14-25 mesh), e.g., by heating the screen combination, e.g., by blowing heated air on it or by passing the screen combination beneath a heated top roller or through a pair of opposed rollers with the top roller of the pair heated, thus heating the top layer(s) of screening material to facilitate the gluing together of multiple layers, e.g. heating to at least about seventy degrees F. and preferably between seventy degrees F. and two hundred fifty degrees F., with about one hundred degrees used in one embodiment; to facilitate the curing of the glue by cooling it, e.g., by cooling a roller beneath the screen combination or by cooling a lower roller of the roller pair referred to above and/or by blowing cool air on the curing glue; plastic coating on a roller inhibits the sticking of glue to the roller, e.g., but not limited to applying polytetrafluoroethylene sheets, fabric, pieces, or tape (smooth or textured) to a roller; using such a tape, sheet, piece, fabric etc. that has a texture, pattern, or projecting parts or portions imparts a corresponding texture, etc. to glue on the screen combination that comes in contact with the texture, etc. and that such a resulting texture, etc. formed in the glue is advantageous because it enhances contact between the glue and screening material, provides structure that xe2x80x9cgrabsxe2x80x9d the screening material thus facilitating its passage through the rolls, and inhibits channeling down a glue line; and that rolls of glued-together screen combination can be produced which are relatively long as compared to the length of a single shale shaker screen assembly, e.g., but not limited to at least twenty, one hundred, two hundred, four hundred, six hundred, or eight hundred foot long rollsxe2x80x94which in certain aspects are rolled up with a release layer or liner, or a separator which, in certain aspects, is kraft paper silicone coated on both sides. This inhibits or prevents parts of the glued screening material from adhering to each other as glue cures.
The screening material fed through such machines may be any desired dimensions, including, but not limited to, dimensions corresponding to the typical lengths or widths typically used to make known screens for shale shakers. PUR hot melt glue, e.g., but not limited to, commercially available Henkel R 183 B Glue from the Henkel Co. or similar glues may be used.
In certain aspects, using a xe2x80x9cnipxe2x80x9d or dual opposed rollers (optionally under pressure) between which multiple screen layers being glued together are passed, glue moves and/or is squeezed upwardly between mesh in the screening layers. In one aspect a bottom nip roller (in one embodiment coated with a non-stick substance or tape) pushes up against a lower surface of a bottommost screen layer, preventing glue from moving down and out from the screen layer. Optionally, such a bottom roller may be cooled (by any known method and/or device or apparatus, including but not limited to, those disclosed or referred to herein), thus increasing the viscosity of at least lower portions, if not a large portion of the glue and inhibiting downward travel of the glue. The wires or strands of the mesh(es) restrict side-to-side glue movement and the glue, therefore, can only travel up into layers above a layer or layers to which the glue was initially applied. Optionally, the top roller is heated by any known method and/or device or apparatus (including, but not limited to, any disclosed or referred to herein), which heats upper parts and/or layers of mesh(es) which results in the heating of upper portions of glue that has been applied to one or more layers, thus reducing the viscosity of these portions and facilitating upward passage of the glue through the upper layer(s) of screening material. Optionally the two rollers are forced together (in one aspect a pressure between about twenty to about fifty p.s.i.) squeezing screening layers together and forcing glue to move up through the mesh of the layers.
The present invention, in certain aspects discloses a screen assembly with layers glued together by, e.g., heated (then cured) moisture-curing hot melt glue, and methods for producing such glued screen assemblies.
The present invention, in certain aspects, provides a screen assembly made by an automated method according to the present invention. In certain embodiments of such methods moving mechanical apparatus powered e.g. by electricity or by fluid driven power apparatus (e.g. but not limited to, apparatus powered by fluid under pressure, e.g., but not limited to, hydraulic fluid under pressure powering hydraulic pumps and/or motors) applies glue in a desired pattern to one, two, three or more layers of screening material. Upon curing, the glue holds together screen assemblies according to the present invention which have one, two or more layers of screening material, bonded together or not, connected together or not, with or without a lower support structure, and with or without side hookstrip mounting apparatus. Any suitable screening material disclosed herein or disclosed in any patent or application referred to herein may be used. In one aspect screening material is used suitable for a screen assembly for screening drilling fluid introduced to a shale shaker that has one or more such screen assemblies. In certain aspects the glue used for applying a glue pattern is such that it rests on top of the screening material even in an uncured or un-set state and does not fall through or out from the screening material and rests on it for further steps in the method, or is such that if it does tend to move downwardly through layer(s) of screening material its rate of movement is such that (and it is sufficiently viscous and/or it is sufficiently cured) it does not fall out from the screening assembly.
In certain methods that are automated according to the present invention, powered mechanical movement apparatus moves the layer(s) of screening material with respect to glue application apparatus. In one aspect the powered moving mechanical apparatus uses a patterned roller to apply glue in a pattern to screening material. In another aspect, one, two or a larger plurality of glue nozzles are moved above the screening material (which itself may be stationary or may be moving beneath the glue nozzles) to apply the glue in a desired pattern. In one particular aspect a plurality of spaced-apart glue dispensers on a manifold are moved above the screening material. In certain aspects the manifold is oscillated with respect to the screening material and, in one aspect, there are two, three or more such manifolds. Any desired glue pattern may be applied. A screen or screen assembly thus made according to the present invention may, optionally, be mounted to lower support, such as a tubular frame, on a strip support, rod support, on a layer of coarse mesh or gridwork, or on a perforated plate or perforated piece of sheet metal. Such mounting may be any suitable known method disclosed in the art and any suitable known frame, strip support, rod support, coarse layer, or perforated plate may be usedxe2x80x94including, but not limited to, those disclosed in any patent or application referred to herein. Alternatively, according to the present invention, hookstrips may be applied on spaced-apart sides of glued screening material(s).
In certain aspects of methods according to the present invention glue is applied with at least two nozzles so that lines of glue intersect and, at points of intersection, the glue pattern is stronger (due to the fact there is relatively more glue present at such points) than at points along either glue line where the lines do not intersect.
The present invention discloses, in at least certain aspects, a screen made by a method for making a screen for a vibratory separator, the method including placing a substrate or at least one layer of screening material below a glue application apparatus, the glue application apparatus including a main body and a plurality of movable glue nozzles movably connected to the body, and applying with the movable glue nozzles an amount of glue in a pattern to at least a portion of the substrate or to the at least one layer of screening material by moving the movable glue nozzles over the substrate or over the at least one layer of screening material. In one such method in which a glue pattern is applied to a substrate, the glue pattern while still manipulable is removed from the substrate and is then applied in pattern form to screening material.
The present invention discloses, in certain embodiments, a screen for vibrating screen apparatus. The screen has one or more upper layers of screen, screen cloth, and/or mesh. The layer or layers may be mounted on frame apparatus which may include a solid side support on each of two spaced apart sides of the layer(s), or a full four sided screen frame, with or without one or more interior crossmembers such as tubular rods or hollow tubular members extending between the sides. A strip support or strips of support material (e.g. flat steel) may be used beneath screen layer(s). In some aspects, hookstrips are used on opposed sides or ends of a screen made by a method according to the present invention so that it can be mounted in a shaker or other separator apparatus. Any known hookstrip configuration may be used according to the present invention.
The present invention, in one embodiment includes a shale shaker with a frame; a xe2x80x9cbasketxe2x80x9d or screen mounting apparatus; one or more screens according to the present invention as described above and below; and basket vibrating apparatus.
The present invention discloses, in certain aspects, a screen made by methods for making screens and screen assemblies as disclosed herein for a vibratory separator, the methods including placing at least two layers (in some cases two, three or four layers) of screening material adjacent one another one on top of the other, introducing an amount of glue to the at least two layers of screening material for adhering at least portions of them together, the amount of glue introduced to the at least two layers of screening material from one, two or more manifolds each with a plurality of glue dispensing nozzles or tubes above screen layer(s) moved beneath the manifolds.
It is, therefore, an object of at least certain preferred embodiments of the present invention to provide:
New, useful, unique, efficient, non-obvious methods for making glued screens and screen assemblies, and such methods using powered moving mechanical apparatus for applying heated glue in a pattern to one or more layers of screening material and, in one aspect, with powered mechanical apparatus for moving the screen layer(s) beneath the glue apparatus screen assemblies with multiple layers of screening material;
Such methods for making screen assemblies with one or more lower coarse screen members and one or more upper fine screen members; such screens with a lower support beneath the screen layers and, in one aspect, with one or more bottom strip members, support strips or rods; such screen assemblies with a lower support frame or a lower support perforated plate; such screen assemblies in which screening material of adjacent screen layers is glued together with glue, e.g. but not limited to, moisture-curing hot melt glue; and shale shakers or vibratory separators with any such screen assemblies;
Such methods for making screens or screen assemblies with a gluing system that has one, two or more manifolds each with a plurality of spaced-apart glue dispensers for applying a pattern of glue to screen layer(s) moving beneath the manifolds; and, in one aspect, with hot-melt glue sufficiently viscous to stay on a layer or layers of screening material to cure and glue the layers together;
A shale shaker or vibratory separator with one or more such screens or screen assemblies; and
Methods of making such screens and machines for making them.
The present invention recognizes and addresses the previously-mentioned problems and long-felt needs and provides a solution to those problems and a satisfactory meeting of those needs in its various possible embodiments and equivalents thereof. To one of skill in this art who has the benefits of this invention""s realizations, teachings, disclosures, and suggestions, other purposes and advantages will be appreciated from the following description of preferred embodiments, given for the purpose of disclosure, when taken in conjunction with the accompanying drawings. The detail in these descriptions is not intended to thwart this patent""s object to claim this invention no matter how others may later disguise it by variations in form or additions of further improvements.